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Question: What’s the difference between .htm and .html?

Question: What’s the difference between .htm and .html? Chuck Heath <[email protected]> asks, "Does the difference imply a different OS? Many Macintosh-related URLs end with .html, but other .html URLs are clearly non-Macintosh. Does .htm mean it’s a Windows or Unix system?"

Answer: The suffix on a file doesn’t tell you anything about the operating system. Macintosh, Unix, and Windows operating systems each treat filenames somewhat differently. And, with the release of Windows 95 over two years ago, the old DOS-style 8-dot-3 naming convention went out the window – sort of.

In the old days, before Windows 95, Windows 3.1 and its predecessors could only name files with up to eight characters, a dot, and then up to three characters. Macs have always been able to handle 31 characters, and Unix’s limit varies, but it’s at least 64 characters in most versions. Windows 95 added long filenames, allowing up to 250 characters.

However, even Windows 95 rewrites filenames down to 8-dot-3 when you copy files to a floppy disk or over certain kinds of networks. Many people working in multi-platform environments choose to name their files with 8-dot-3 filenames to make sure the names don’t change as they pass from machine to machine.

Fortunately, as with everything these days, there’s a utility that can help you manage cross-platform file conventions called HTML Rename.

<http://www.visiontec.com/rename/>

So seeing .HTML means the server isn’t a Windows 3.1 machine, but seeing .HTM doesn’t necessarily tell you anything. [GF]


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